L-theanine as a promising agent on brain health-promoting foods – A review

Abstract

With the aging of the population and the growing pressure of social competition, brain-related neurodegenerative diseases and mental disorders increasingly affect our quality of life and place a huge burden on health systems around world. L-theanine is a unique non-protein amino acid from tea leave, and now commercially available as a safe food ingredient in the market. This review summarizes the studies on the effects of L-theanine on various mental and brain conditions, including mental stress, anxiety, insomnia, depression, poor learning ability and memory, neurodegenerative diseases, and discusses its potential application in functional foods for brain health.